1. Field of the Invention
The present invention relates to a projector of a reflection type. More particularly, the present invention relates to a projector of a reflection type in which a transparent original can be set easily.
2. Description Related to the Prior Art
A reflection type of overhead projector is used for presentation of an image to a considerable number of viewers. A projector body has a top face as a stage, where a transparent sheet or original is placed. When the overhead projector is used, a projector head is set above the stage and at the top of a stay. The projector head protrudes over the projector body in such an extended manner that it is likely to obstruct a view of some of the viewers.
JP-A 4-155323 discloses a reflection type of projector in which the projector body incorporates elements of the projector head inclusive of a lamp, a flat mirror and a projecting lens, and which is characterized in a reduced thickness of the overall orientation during the use. The projector of the reflection type has a cabinet, having a top face in which an opening is formed. The opening is covered by a transparent stage plate to define the stage. An original sheet cover is mounted on the stage to cover the original sheet placed on the stage, and supported in openable fashion. A Fresnel mirror is fitted inside the sheet cover. When the sheet cover has a closed state, the Fresnel mirror is contacted on the original sheet. The projecting lens is disposed beside the cabinet, which incorporates the lamp and the flat mirror. The flat mirror reflects light from the lamp toward the original sheet. The light transmitted through the original sheet is reflected by the Fresnel mirror, and then reflected by the flat mirror again toward the projecting lens.
The projector of the reflection type, however, has a drawback of inefficient operation in that the sheet cover must be opened and closed each time the original sheet is set properly or adjusted in position during the projection. Problems lie in difficulties in positioning the original sheet. It is likely that the original sheet is shifted by wind pressure of the sheet cover when the sheet cover is closed with the original sheet placed on the stage. When the projector of the reflection type is installed in an inclined orientation, the original sheet is likely to drop away from the stage.
To solve those problems, there are plural suggestions of the projector of the reflection type having a sheet feeder unit. The sheet feeder unit is disposed on the top of the cabinet. Plural transparent originals are set on a feeder tray. The projector of the reflection type is remotely controlled to convey the original sheet to the stage.
The projector of the reflection type having the sheet feeder unit can be loaded with the plurality of transparent originals. Also a remote control device can be operated to exchange the original sheets one after another in a position distant from the projector of the reflection type. Those are advantages for the presentation by projecting images in a predetermined order in a large room or hall. However the projector of the reflection type with the sheet feeder unit is difficult to use for effecting presentation while the original sheet is corrected by handwriting or partially changed, or the order of the originals is changed, particularly in a small hall. An additional problem lies in high cost for incorporating the remote control device in the projector of the reflection type.